Sulphur dye composition and method of manufacture



Patented Apr. 10, 1945 SULPHUR DYE COMPOSITION OF MANUFACTURE AND. METHOD Ewen D. Robinson and John C. Boesch, In, Mount Holly, N. 0., assignors to Southern Dyestufl Corporation, a corporation of North Carolina No Drawing. Application December 22, 1941,

Serial No. 423,991

Claims.

sulphur type of dyestuff. The use of sulphur dyes, generally speaking, has been limited heretofore in the printing art, as distinguished from dyeing, since they normally contain sulphides as reducing agents and these sulphides have a corrosive action on the metal printing plates or rolls.

Common examples of such sulphides are sodium sulphide, sodium hydrosulphide and sodium disulphide. The deleterious efiects of these reducing agents have definitely limited commercial use to date of the sulphur dyes for printing of fabrics. In accordance with our present invention we have produced a. sulphur dyestuil that is entirely (or. 8-37) V The printing composition of our invention may be employed in the usual way for printing of suitable for printing purposes in view of the fact that it does not require any sulphides or similar reducing agents. We have discovered that a new while omitting the usual sulphide reducing agents Y and in fact all other reducing agents, if desired.

The amines function apparently as solvents or dispersing agents for the dyestuil and convert the latter into a state of extremely finesubdivision, at least of colloidal size and in some instances perhaps of molecular size. This produces a liquid printing composition in the form of a colloidal dispersion or true solution; which we shall refer to hereinafter as a solution. The solution may be prepared in either 'weakor concentrated form as desired. In a commercially advantageous form the solution is capable of being filtered.

We are aware thatamines generally have been proposed heretofore ifor replacing the alkali in dyeing and printing compositions intended for use on wool, which would be damaged by the alkali. However, these compositions still employ the reducing agents such'as sulphides and are objectionable for the reasons. given above. Furthermore, we have found in actual practice that show an appreciation of the feature inherent in our invention; that is, certain amines may be used in alkali solution in lieu of the usual reducing agents.

fabrics. This normally involves the mixing of the dyestufi solution with a suitable printing paste (which may contain starch, gum, or synthetic printing materials) that gives the dyestufl' proper viscosity for use on the printing machines.

In preparing the printing composition of our invention practical use may be made of the moist press cake that is commonly produced in the manufacture of sulphur dyes: and it is not-necessary to dry the sulphur colors to the usual dry powder form. The moist dyestufl press cake is easily dissolved or dispersed in an alkaline solution of an ethyleneamine. In the usual case a press cake of the sulphur colors, such as for example, sulphur black, blue, green or yellow, or any other desired sulphur color, is dissolved in a, caustic or other suitable alkali solution of the amine. The mixture is advantageously heated to accelerate the desired solubilizing effect of the amine or amines on the sulphur colors; although, in certain cases no heat is required. Generally speaking, the temperature may vary from about room temperature up to the boiling point of the solution. An example of the latter is about 110" C.

The amines that/wehave found suitable for dispersing or dissolving the dyestuffs include the ethylene and polyethylene amines. Examples of such amines are: ethylenediamine; diethylenetrlamine; triethylenetetramine; tetraethylenepen- 'tamine; pentaethylenehexamine. These amines may be" classified as straight chain, aliphatic amines: including both primary and secondary amines. Suitable examples of the amines useful in our invention may be represented by the following formula:

(oinonrimnmnn in which a:=a whole number from l to? i1=a number between '0 and 4 and always one less than 0:.

In our compositionany one of the above repreture of the polyethyleneamines comprising diethylenetriamine, triethylenetetramine and tetraethylenepentamine. These amines, in'a 25% solution, have a pH value of around 12, and the final amass: 3 ing a sulphur dyestul'l press cake with an alkali 8. A sulphur dyestuiis solutionwhich is free of and a straight chain amine having the following the usual corrosive sulphides, hydrosulphites and formula: sulphites or other corrosive reducing agents and (Cal-I4) :(N'HalflNHh which in place thereof contains in combination in which z=a whole number from 1 to 5, =a number between 0 and 4 and always one less than 1:, and heating to street a substantially uniform solution of the several components.

4. A liquid, sulphur dyestufls composition that is adaptable for printing and is substantially free Of corrosive, agents, comprising an aqueous, alkaline, solution or dispersion or sulphur dyestufl and an openchain, aliphatic amine having the following formula:

wimmmnmmm in which m=a whole number from 1 to 5 and y=a number between 0 and 4 and always one less than 1:.

5. A liquor sulphur dyestuils composition comprising a substantially non-corrosive, alkali solution or dispersion of unreduced sulphur dyestufl's substantially free 01 sulphide, sulphite, and hydrosulphite or other corrosive reducing agents, and an amine having the iollowing i'ormula:'

in which a:=s. whole number from i to 5 and y==a number between 0 and 4 and always one less than :c.

sulphide and hydrosulphite reducing with the sulphur dyestufis a substantial amount 01' an open-chain, aliphatic amine having the formula (Cal-I4) :(NHs) 2(NH) y in which x=a whole number from 1 to 5 and pentamine.

10. In the process 01' producing a non-corrosive, sulphur dyestuii adaptable for printing textiles and substantially free of reducing agents,

the step of finely dispersing the sulphur dyestulf in an alkaline solution of a straight chain, aliphatic amine having an ethylene group, the dispersed dyestuil being flltrableand useful in a printing composition;

- EWEN D. ROBINSON. JOHN C. BOESCH, Js. 

